Democrats in Congress will subpoena the full report of special counsel Robert S. Mueller III if the Justice Department only discloses certain parts of it, Sen. Richard Blumenthal said Thursday.

The Connecticut Democrat is a key member of the Senate Judiciary Committee. Republican Sen. Lindsey Graham of South Carolina is the committee’s chairman, and has subpoena power over the Justice Department.

CNN reported Wednesday that Mueller could issue a report on Russian interference in the 2016 U.S. elections as early as next week, though the special counsel’s notoriously tight-lipped office has provided no timeline for its plans.

Newly confirmed Attorney General William Barr was noncommittal in his confirmation hearing about whether he would allow Mueller to testify before Congress, and whether he would resist a subpoena for the special counsel’s report.

Blumenthal told CNN’s “New Day” that he is optimistic Graham would join Democrats in the House in subpoenaing the Mueller report. Democratic Chairman Jerrold Nadler of the House Judiciary Committee has said the full report should be made public.

“There’ll be subpoenas from Congress, including, I hope, from the Senate Judiciary Committee,” Blumenthal said.

“If necessary, our committee will subpoena the report. If necessary, we’ll get Mueller to testify,“ the New York Democrat told CNN in January. “The American people need the information here.”

Shielding most of Mueller’s report, and issuing select bits and pieces, would create the “public perception of a cover-up,” Blumenthal warned Thursday.

“If William Barr believes — I think he does — that a sitting president cannot be indicted — I disagree with him — and he brings no charges that Mueller says can’t be brought, and if there are no public disclosures, the public rightly will feel that there is a cover-up,” Blumenthal said.

But could the House and Senate actually enforce a subpoena of Mueller?

“A Senate or House Committee may subpoena anyone. The Department of Justice may resist it,” Blumenthal clarified Thursday.

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If Barr both denies lawmakers’ request to publicize the report and resists any subsequent subpoenas, that could set up a drawn-out court battle between Congress and the executive branch over the document’s disclosure.

Even if the Mueller report remains shrouded in mystery for months, President Donald Trump, whose 2016 campaign faces accusations of cozying up to foreign influences including Russia, Saudi Arabia, and others, is still not in the clear.

“Donald Trump’s legal exposure is far from over” despite the Mueller investigation appearing close to its end, Blumenthal said. He cited the continuing spinoff investigations in the Eastern District of Virginia and Southern District of New York.

Those investigations have led to the convictions of multiple Trump campaign officials, including the president’s former personal lawyer Michael Cohen and campaign chairman Paul Manafort.